The Pohl books I've kept are
Plague of Pythons, plus a couple he co-wrote with Kornbluth:
The Space Merchants and
Wolfbane.
Now I do not doubt that the great majority of people would say that his later work is far better literature, and I wouldn't disagree. But the early 'golden age' stuff is so fresh and vigorous that I find it appealing. Also, I read these when I was deep into discovering SF, as a teenager four decades ago, so they'll always have a nostalgic appeal. And they're very short by modern standards, so your investment in time is small
.
When it comes to deciding which books to keep for re-reading, I find I'm much tougher on the fat modern multi-volume series - not just because they use up so much precious shelf space, but also because they have to be absolutely brilliant before I'm willing to set aside the time needed to slog through them all over again...